Cytology of the highly polyploid disjunct species, Allium dregeanum (Alliaceae), and of some Eurasian relatives

Chromosome numbers are given for 16 taxa in Allium Section Allium , three in Section Codonoprasum , two in each of Sections Molium and Rkizirideum and one in each of Sections K'aloprasum, Megaloprason and Melanocrommrum. The basic chromosome number is x = 8 in all except Section Molium , in which the studied species unusually have x = 7. Polyploid) is common in the genus, with over half of the studied taxa in Section Allium having polyploid representatives. The highest ploidy levels found so far in the genus occur in A. dregeanum (2n = 8x = 64 and 10x = 80), which is counted here for the first time. Although highly polyploid, this disjunct South African species forms only bivalents during meiosis. The chiasmata are proximal, an uncommon phenomenon reported also in hexaploid 1. nm-peloprasum. Although A. dregeanum is genetically related to A. ampeloprasum , the suggestion that it is a cultivated variant of that species introduced to South Africa by the early settlers is unlikely.     

Two New Species of Allium L. from Sichuan

This paper reports two new species of Allium L. from Sichuan, A. xiangchengense J. M. Xu and A.guanxianense J. M. Xu. The former is related to A. hookeri Thwaites, but differs from it by its lanceolate to linear-lanceolate leaves with evidently contracted base and filaments longer than the tepals, while the latter is related to A.chienchuanense J. M. Xu, but differs from it by its terminal scape, filaments shorter than the tepals and ovary with solitary ovule in eachlocule.     

Tulipa intermedia sp. nov. (Liliaceae) from the Ferghana Depression,Uzbekistan

A new species, Tulipa intermedia, collected in the Ferghana Depression is described. The new species belongs to section T. sect. Kolpakowskianae Raamsd. ex Zonn. & Veldkamp. It is similar to T. scharipovii Tojibaev and T. talassica Lazkov but is distinguished by morphological characters of bulbs and flowers and by its ecology, growing only in Artemisia steppe on plains and in low foothills with gravelly slopes. From T. scharipovii, the new species differs by non‐coriaceous and strongly prolongated bulb tunics, pubescence of tunics, shorter stem, shape of outer petals and filaments, and by its pale yellow (not green) bottle‐shaped ovary. Two varieties of T. intermedia differing in the colour of tepals and filaments were observed growing together and are formally described.     

Involvement of abscisic acid (ABA) in bulb dormancy of Allium wakegi Araki I. Endogenous levels of ABA in relation to bulb dormancy and effects of exogenous ABA and fluridone

Allium wakegi plants exposed to long days (LD, 14 h-photoperiod) developed bulbs, which were dormant from the 30th to the 125th day of LD, but those grown under natural short days (SD) did not develop bulbs. The contents of abscisic acid (ABA) in both whole bulbs and buds of the bulbs increased in LD, reaching a maximum at the 60th day of LD and decreasing thereafter, but those in basal leaf sheaths (this part corresponds to a bulb after bulb development) and buds did not increase in SD. The ABA content was related to the depth of bulb dormancy. Application of 500 M ABA to bulbs for 24 h significantly delayed sprouting, but that of 5 or 50 M ABA had little or no effect. Application of 25 or 125 M fluridone to the soil just before exposure to LD bleached new expanding leaves and reduced bulb size, but had no effect on the development of bulb scales that characterize bulb formation. The bulbs formed under such conditions sprouted earlier than those of control plants. The levels of endogenous ABA in bulbs, buds of the bulbs, leaf blades, and roots were reduced by fluridone application. These results indicate that ABA plays an important role in bulb dormancy of Allium wakegi.     

Variation in economically and ecologically important traits in onion plant organs during reproductive development

The spatial distribution of organosulphur compounds throughout the onion (Allium cepa L.) plant body during reproduction is of ecological and horticultural interest. These secondary metabolites are associated with both pest resistance and many of the vegetable's culinary and medicinal properties, including the ability to inhibit platelet aggregation. Inhibition of platelet aggregation can be of benefit to human cardiovascular health. Organosulphur compound concentrations are associated with elemental sulphur, pungency, soluble solids and effect on human platelet aggregation. These parameters were evaluated in extracts collected separately from bulb scales, leaf blades, scapes and umbels biweekly throughout the reproductive phase of the life cycle of the onion. Significant variation in pungency, platelet inhibition, total sulphur content and soluble solids existed among samples of organs and within organs over time during reproductive growth. Furthermore, some extracts from leaf, scape and bulb induced rather than inhibited platelet aggregation.     

Phylogenetic reappraisal of Allium subgenus Cyathophora (Amaryllidaceae) and related taxa,with a proposal of two new sections

The phylogeny of subgenus Cyathophora and representatives of its closely related taxa within Allium were reconstructed based on nrDNA ITS and two plastid fragments (trnL-F and rpl32-trnL). The constructed phylogenies indicated that subgenus Cyathophora was not monophyletic and to be split in three parts positioned in different clusters. Allium kingdonii was unequivocally placed within subgenus Amerallium and formed an immediate sister relationship with New World Amerallium clade, suggesting an unexpected intercontinental disjunct distribution. For another, Allium trifurcatum was firmly nested within subgenus Butomissa next to A. tuberosum and A. ramosum, but it is distinctly different morphologically from the latter by thinly leathery bulb tunics, uniovulate locule and obviously 3-cleft stigma. Based on the geographic features, morphological and molecular evidences, two new sections, Kingdonia X.J.He et D.Q.Huang for A. kingdonii and Trifurcatum X.J.He et D.Q.Huang for A. trifurcatum, were proposed. The remaining three species of subgenus Cyathophora formed a well-defined clade, and the phylogenetic relationships among them recovered were consistent with previous findings. In addition, A. weschniakowii and A. subtilissimum were proven to be a member of subgenera Rhizirideum sensu stricto (s. str.) and Cepa, respectively, rather than subgenera Cepa and Polyprason previously proposed. Section Rhizomatosa represented by A. caespitosum should be subsumed within section Caespitosoprason of subgenus Rhizirideum s. str.     

Diversity in fertility potential and organo-sulphur compounds among garlics from Central Asia

Extending the collection of garlic (Allium sativum L.) accessions is an important means that is available for broadening the genetic variability of this cultivated plant, with regard to yield, quality, and tolerance to biotic and abiotic traits; it is also an important means for restoring fertility and flowering. In the framework of the EU project Garlic and Health, 120 garlic accessions were collected in Central Asia – the main centre of garlic diversity. Plants were documented and thereafter maintained in field collections in both Israel and The Netherlands. The collection was evaluated for biological and economic traits. Garlic clones vary in most vegetative characteristics (leaf number, bulb size and structure), as well as in floral scape elongation and inflorescence development. A clear distinction was made between incomplete bolting and bolting populations; most of the accessions in the latter populations produced flowers with fertile pollen and receptive stigma. Wide variations were recorded with regard to differentiation of topsets, their size, number and rapidity of development. Furthermore, significant variation in organo-sulphur compounds (alliin, isoalliin, allicin and related dipeptides) was found within garlic collections and between plants grown under differing environmental conditions. Genetic fingerprinting by means of AFLP markers revealed three distinct groups within this collection, differing also in flowering ability and organo-S content.     

Effect of long photoperiod on the reproductive and bulbing processes in garlic (Allium sativum L.) genotypes

Garlic (Allium sativum L.) genotypes differ considerably in scape length, flowering ability, and seed production. In bolting clones reproductive processes are facilitated by a combination of specific temperature and photoperiod regimes. However, it is yet unclear whether the phase-specific photoperiod effect on florogenesis is universal for all garlic genotypes. We investigated the effect of ambient day length interruption by 10 or 30 days of long photoperiod in ten garlic accessions belonging to four bio-morphological groups. It was evident that garlic genotypes vary significantly in response to long photoperiod, and that in some clones the treatment enhances florogenesis, flower stalk elongation and bulbing. The competition for resources by the simultaneously developing bulb and inflorescence sinks differentially determines the fate of stalk elongation and flower development in the investigated genotypes. It is concluded that florogenesis in garlic can be promoted by exposure to proper environmental stimuli, during pre-planting storage and sprouting to the later growth stages. The genetic variability acquired from sexual reproduction and vegetatively preserved collections can serve in genetic and physiological studies as well as in breeding programs.     

A Study on Karyotype Differentiation of Allium fasciculatum (Liliaceae)

Karyotypes of three local populations of Allium fasciculatum Rendle were analyzed. The karyotype of the population from Dagze of Xizang was 2n=2x＝20=4m+10sm +4T+2t(2SAT), the one from Xiangcheng of Sichuan was 2n=2x＝20＝10sm+6t(2SAT)+4T, and the one from Lixian of Siehuan was 2n＝2x=20＝6m+10sm+2t (2SAT)+2T. Although there were differences in karyotypes among the three populations, they were very similar in morphological characters, except that plants in the Dagze population were lower. The karyotype of the Lixian population is considered to be a primitive one that has evolved into the more asymmetrical karyotypes of the Dagze population and Xiangcheng population by structural aberration. In the genus Allium, only four species, A. fasciculaturn, A. decipiens Fisch., A. kujukense Vved. and A. cheloturm Wendelbo. have so far been found to have the basic chromosome number of x＝10. According to karyotype characters and the distribution pattern of these four species, the basic number x = 10 may have different origins. At least that of A. fasciculatum is different from that of the other three species and might have originated the latest. A. fasciculatum was similar to A. hookeri Thwaites (the latter has x＝11) in karyotypical and morphological characters. Therefore, they are considered to have originated from a common extinct ancestor that had the basic number of x = 10.ey words Allium;A．fasciculatum Rendle;Karyotype differentiation     

粗根韭的核型分化研究

对葱属粗根韭的3个地方居群的核型分析结果表明,3个居群的核型表现出很大的差异。西藏 达孜居群为2n=2x=20=4m+10sm+2t(2SAT)+4T;四川乡城居群为2n=2x=20=10sm+6t (2SAT)+4T;四川理县居群为2n=2x=20=6m+1Osm+2t(2SAT)+2T。虽然它们之间在核型上存 在差异,但除达孜居群的植株较矮小外,3个居群的植物在形态上却非常一致。理县居群的核型被认为 是原始类型,由它通过染色体结构变异,分别演化出更不对称的达孜居群和乡城居群。葱属中,目前只 发现4个种的染色体基数为10,除本种外其余3种分别是A．decipiens Fisch．;A．kujukense Vved．和 A．chelotum Wendelbo。根据这4个种的核型特征和分布格局,基数10可能有不同的起源,至少粗根韭 的起源与其余3种不同,而且起源最晚。粗根韭的核型特征及它与染色体基数为11的宽叶韭A．hook- eri Thwaites在核型上的相似性,表明它们很可能共同起源于基数为10但现已绝灭的祖先种。此外,还探讨了该祖先种的起源问题。     

BULB ORGANIZATION IN ALLIUM: SOME SPECIES OF THE SECTION MOLIUM

Mann , Louis K. (U. California, Davis.) Bulb organization in Allium: some species of the section Molium. Amer. Jour. Bot. 47(9) : 765–771. Illus. 1960.—Bulb development and organization are described for Allium neapolitanum, A. erdelii, A. hirsutum, A. subhirsutum, A roseum, and A. zebdanense, species of Molium, a Mediterranean section of the genus. These species begin growth in the late fall or midwinter, flower in March and April, and are dormant throughout the summer. The plant axis is commonly a sympodium made up of one or more branches terminated by inflorescences and a final branch ending in a large renewal bulb.. This bulb and one to many increase bulbs are formed each season. The bulbs mature by flowering time or shortly thereafter and the other parts—stem, leaves, roots, etc.—of the current season's plant die. Little change is evident within the bulbs during the summer rest period, but in September and October (or later in one species) the inflorescence and renewal bulb primordia appear. Five distinct types of leaves make up the bulb, including foliage leaves, food-storage leaves, and leaves which develop a heavy sclerotic layer around the bulb. The similar bulb structure of the 6 species indicates their close relationship. The 2 leaves which form the protective layer around the bulb become fused by the time they reach maturity, a condition apparently unique for the section Molium.     

The effect of far-red light on the photoperiodic regulation of carbohydrate accumulation in Allium cepa L.

Carbohydrate accumulation was induced in Allium cepa L. cv. Dorata di Parma by the addition of far-red light throughout the 18 h day. Neither an 18 h-day without far-red nor the addition of far-red light to a 10 h photoperiod could induce the carbohydrate accumulation. The accumulation of reducing sugar takes place both in the leaf-blades and in the bulb; while there is accumulation of oligosaccharides only in the bulb. The results implicate phytochrome in the promotion of carbohydrate accumulation by far-red light.     

Echeveria yalmanantlanensis (Crassulaceae): A new species from Cerro Grande, Sierra de Manantlán, western Mexico

Echeveria yalmanantlanensis, a new species from eastern Sierra de Manantlán, Biosphere Reserve, on the Jalisco-Colima border in western Mexico, is described and illustrated, and a table for comparison of morphologically related taxa is provided. This species belongs to series Valvatae, differing from the other members of the series by its acaulescent habit, shape and color of leaves and bracts, size of scape, bract pattern on scape, size and color of the corolla, habitat, and geographic distribution. There is support for the hypotheses that this species is endemic to the calcareous massif Cerro Grande and is already in danger of extinction.     

Bulbing in Onions: Photoperiod and Temperature Requirements and Prediction of Bulb Size and Maturity

Bulb size and maturity are key characteristics of an onion cropand the onset of bulbing is an important determinant of these.In this paper we describe an experiment in which bulb and neckdiameter and leaf number were measured in onion crops (cultivarsPukekohe Longkeeper and Early Longkeeper) with different sowingdates planted at two different locations in New Zealand. A sensitiveindicator of earliest time of bulbing was developed using theratio of bulb and neck diameters and the statistical techniqueof cusums. Bulb diameter at bulbing was related to thermal timeaccumulated prior to bulbing. Bulbing only occurred when dualthresholds of a minimum thermal time of 600 degree days anda photoperiod of 13.75 h were reached. Mathematical relationshipswere developed between leaf number, sowing date, bulbing dateand bulb growth and maturity. Final bulb size could be predictedfrom bulb size at bulbing and number of leaves produced afterbulbing. Bulb maturity date could be predicted by number ofleaves after bulbing. Allium cepa L.; onion; temperature; photoperiod; bulb-neck ratio; leaf number; bulbing     

Pollen morphology of some taxa of Vicia L. subgenus Vicilla (Schur) Rouy (Fabaceae) from Turkey

The pollen morphology of the ten taxa belonging to Cassubicae Radzhi, Cracca Dumort., Ervilia (Link) Koch, Lentopsis Kupicha, Trigonellopsis Rech. f. and Variegatae Radzhi sections of the genus Vicia L. subgenus Vicilla (Schur) Rouy (Fabeae, Fabaceae) in Turkey has been examined by use of light microscopy and scanning electron microscopy. Twelve morphometric characters are analysed with one-way analysis of variance and Tukey’s honestly significant difference test for multiple comparisons. Polar axis and equatorial diameter of pollen grains range from 24.64 to 44.19 and from 15.90 to 30.42 μm, respectively. The pollen grains are prolate–spheroidal to perprolate (P/E = 1.09–2.07), but the prolate shape occurs in the majority of the taxa. The regular pollen grains of all taxa are trizonocolporate, isopolar, and released in monads. Ornamentation of the mesocolpium is psilate–perforate in V. tenuifolia subsp. dalmatica and V. tenuifolia subsp. tenuifolia (sect. Cracca), reticulate–rugulate in V. villosa subsp. villosa (sect. Cracca), and reticulate–perforate in the remaining taxa. The apocolpium and colpus area are reticulate–perforate in V. hirsuta (sect. Cracca), V. ervilia (sect. Ervilia) and V. lunata subsp. grandiflora (sect. Trigonellopsis), and psilate, psilate–slightly perforate or perforate in the other taxa. The results obtained from analyses of pollen grains from the studied taxa of the subgenus Vicilla reveal significant differences in general morphology and some morphometric attributes, and ornamentation types. However, it is concluded that pollen morphology has proved to be uninformative for differentiating the subgenera Vicilla and Vicia.     

Allium purpureoviride sp. nov. (Alliaceae) from east Anatolia,Turkey

Allium purpureoviride M. Koyuncu & ?. Genç (sect. Melanocrommyum) is described as a new species from east Anatolia, Turkey. The new species is closely related to A. rothii Zucc. from Israel and some characters of the new taxon show similarity with A. cyrilli Ten. and A. asclepiadeum Bornm. The morphological characters of the related taxa are discussed and the distribution of the taxa is mapped. The diploid chromosome number is 2n = 16.